Literacy may have stolen brain power from other functions

The human brain contains many regions that are specialized for processing specific decisions and sensory inputs. Many of these are shared with our fellow mammals (and, in some cases, all vertebrates), suggesting that they are evolutionarily ancient specializations. But innovations like writing have only been around for a few thousand years, a time span that's too short relative to human generations to allow for this sort of large evolutionary change. In the absence of specialized capabilities, how has it become possible for such large portions of the population to become literate?

The authors of a paper that will be released by Science today suggest two possible alternatives to explain this widespread literacy. Either reading is similar enough to something that our brains could already do that it's processed by existing structures, or literacy has "stolen" areas of the brain that used to be involved in other functions. (A combination of the two is also possible.) In the new paper, they use functional MRI imaging of brain activity to figure out just what literacy does to the brain, and discover that literacy does take over some new areas of the brain, with mixed effects on other areas of cognition.